The invention relates to a guide vane ring for a turbomachine. The invention further relates to a gas turbine with such a guide vane ring and to a method for the manufacture of such a guide vane ring.
Known from DE 10 2009 013 819 A1 is a guide vane ring for a turbomachine. This guide vane ring comprises a plurality of guide vanes arranged radially around an axis of rotation, by means of which a flow of gas can be diverted into a turbomachine. The guide vane ring comprises an outer shroud arranged radially on the outer side of the guide vanes and an inner shroud arranged radially on the inner side of the guide vanes. In this case, the guide vane ring is composed of a plurality of individual guide vane ring segments, which are welded together by means of a thermal joining method.
A drawback is that, for especially large dimensions and/or high operating temperatures of the turbomachine, such a guide vane ring cannot withstand the resulting thermal loads without anything further. A possible remedy is either to divide the inner shroud or the outer shroud, so that the outer shroud or the inner shroud has a plurality of expansion joints spaced apart from one another along the peripheral direction. However, a drawback of such expansion joints is that the guide vane ring thereby has leakage. The flow of gas can therefore escape at least partially from the guide vane ring and, in some cases, also thus from the turbomachine. As a result, the efficiency of the guide vane ring and hence also the efficiency of the turbomachine decreases.
Known from DE 6601221 U is a guide vane ring having at least two guide vane ring segments for a turbomachine comprising a plurality of guide vanes arranged radially around an axis of rotation, an outer shroud arranged radially on the outer side of the guide vanes, and an inner shroud arranged radially on the inner side of the guide vanes. The inner shroud has a plurality of expansion joints spaced apart from one another along the peripheral direction. However, these expansion joints do not pass through the entire inner shroud in the peripheral direction, so that high loads can continue to act on the inner shroud.